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Giant Insects

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Allyuh God real experiment with life boy.

They did not hunt humans because there were no humans to hunt, but insects of gargantuan proportions really did exist 300 million years ago.

Bloodthirsty cockroaches plot to destroy humans!

Scientists use fossil DNA to reconstruct gigantic man-eating ants!

Super-sized alien flies invade Earth!

Typical supermarket tabloid headlines? Perhaps. But for decades, frightening mythical images such as these have been prime fodder for monster movies and late night television. The images prey on our fascination and fear of insects.

The enormous insects depicted in bad B movies exist mostly in the realm of science fiction. However, insects of giant proportions really did exist 300 million years ago. They were not as big as dump trucks, but some insects achieved masses many times greater than those of their modern relatives.

The fossil evidence is abundant. Scientists know that dragonflies with wing spans as wide as a hawk’s and cockroaches big enough to take on house cats thrived during the Paleozoic era (245-570 million years ago). At the same time, mammoth millipedes longer than a human leg skittered across prehistoric soil.

Hundreds of different huge species evolved during the late Paleozoic era. The first dinosaurs appeared just about the time the giant insects disappeared.

These ancient giants fascinate Jon Harrison. A physiologist and professor of biology at Arizona State University, Harrison wants to know why giant insects evolved, and why they then disappeared.

The answer may lie in how insects breathe, according to research findings by Harrison and his colleagues. The ASU scientists are busy studying how the respiratory physiology of modern insects affects their body size.

Recent geologic findings opened a new window of thought on this issue. Some researchers are analyzing the composition of ancient soils. Their findings seem to comply with theoretical models. The findings indicate that there was a “pulse” in the concentration of environmental oxygen during the Paleozoic era.

In other words, there was much more oxygen in the atmosphere 300 million years ago than there is today. During this period, the oxygen concentration in the air reached 35 percent, almost double the present level of 21 percent. Oxygen concentration stayed high for about 100 million years, then dropped precipitously to about 15 percent.

Scientists think that the then-recent evolution of oxygen producing land plants caused this oxygen peak. Interestingly, the rise and fall of atmospheric oxygen also coincided with the evolution and extinction of giant insects.

Harrison’s colleagues include Robert Dudley from the University of Texas at Austin, and Jeffrey Graham of the Scripps Institution of Oceanography in La Jolla, Calif. They propose that the temporary overlap between the oxygen peak and the appearance of giant insects was more than just coincidence.

Other researchers had speculated that oxygen availability might limit the ultimate body size for insects. Harrison and his colleagues took the idea a step further. They hypothesized that high ambient oxygen could have permitted the existence of giant species. The demise of winged monsters and behemoth beetles 100 million years later may be explained partly by the simultaneous decrease in the air’s oxygen content.

Harrison says that the amount of available oxygen limits insect body size because of how the creatures’ respiratory systems are made. Instead of lungs, insects breathe with a network of tiny tubes called tracheae. Air enters the tubes through a row of holes along an insect’s abdomen. The air then diffuses down the blind-ended tracheae.

The distance oxygen can travel down the tracheae depends on its concentration in the air. If atmospheric oxygen is doubled, theory says that it should be able to make it twice as far.

According to Graham and Dudley, escalating Paleozoic oxygen levels may have helped speed oxygen transport in the longer tracheae of bigger insects. The environment itself could have opened the respiratory door for Paleozoic insects, allowing giant species to evolve.

sliding scale illustration of the distance oxygen molecules travel based on the amount of oxygen in the atmosphere
Insects do not breath the same way that we do. Oxygen travels to insect tissues through tiny openings in the body walls called spiracles, and then through tiny blind-ended, air-filled tubes called tracheae. For a given tube diameter and temperature, gas molecules diffuse over distance at a rate proportional to the source concentration. In other words, air that contains more oxygen allows the minimum amount needed for metabolism to reach farther into the insect’s tracheae. Some insects canincrease oxygen delivery by a mechanical pumping action of their bodies. Humans and other vertebrates are less likely to be affected by atmospheric oxygen concentration, since oxygen is delivered by blood that is pumped through the tissues.

Harrison’s personal research interest is focused on insect respiratory physiology. The ASU scientist always wondered whether respiration could have been the limiting factor in insect gigantism. Shortly before Graham and Dudley’s hypothesis was published, Harrison learned about the Paleozoic oxygen pulse from Dudley himself.

The two were chatting at a national biology conference. “He told me about the oxygen pulse over a beer. I was stunned and excited by the idea,” Harrison says. “At the time, it was a shock to most of us to think that atmospheric oxygen concentrations could vary. If it did, it seems likely that there would be some fairly strong and interesting physiological consequences.”

The focus of Harrison’s research is Graham and Dudley’s most fundamental assumption: that available oxygen actually limits body size.

Scientists know that the flight muscle of an insect burns more oxygen than any other animal tissue. The amount of oxygen supplied to an insect’s muscles directly depends on the amount of oxygen in the air. Given these facts, it makes sense that giant insects would struggle to get by in a low oxygen atmosphere.

However, Harrison points out that the presumption that the Paleozoic oxygen pulse actually caused the evolution of giant insects rests more on inference than evidence. There are no living giant insects, or fossils of their tracheae.

As a result, biologists are forced to study the next best thing: related species still alive and crawling and flying today. A convincing test of the oxygen pulse hypothesis will depend on the weight of evidence from studies of several species. This takes time. Harrison and his students are contributing to the effort.

“Our work is important because it is the first research I am aware of to experimentally test Graham and Dudley’s hypothesis,” he says.

But until he and others produce the necessary data, Harrison’s good scientific sense requires him to take other possible explanations into consideration.

“There has been a lot of ‘gigantism gone extinct’ in other groups,” he explains.

Some well-known examples are the dinosaurs and the elephant-like mastodons of the Pleistocene era. In these groups, evolution has not been linked to atmospheric oxygen levels, Harrison explains.

“Obviously, there are other environmental or ecological reasons for gigantism and gigantism gone extinct,” he adds.

Some researchers might find this uncertainty unnerving. Harrison is excited by the opportunity to pursue a number of intriguing possibilities. Scribbling chalkboard figures to illustrate his points, he elaborates on numerous other evolutionary scenarios that also could have accounted for the existence of the puzzling giants.

Paleozoic insects may have been able to use other mechanisms, such as respiratory pumps, to increase airflow in their tracheae. If so, giant species could have maximized their ability to breathe even in low oxygen environments.

Ecological factors also could explain the pattern of prehistoric gigantism. For example, some insect biologists favor the idea that giant Paleozoic insects were successful because they were less likely to be eaten. Their massive bodies might have made them more powerful fighters, or made them too big to be considered feasible prey.

Another possible explanation is that increases in ecological diversity may have simply diversified body size options for insects. Being “giant” was just one of the alternatives.

Despite the abundance of competing ideas, the results of Harrison’s experiments suggest that Graham and Dudley’s ideas may well hold up.

In his ASU laboratory, Harrison studies grasshoppers and dragonflies, diminutive modern relatives of the prehistoric giants. He has found that these insects’ activity is affected by the amount of oxygen in the atmosphere.

More importantly, the effect is more pronounced in the largest individuals, which is what the oxygen pulse hypothesis predicts. Since the biggest bugs have the longest tracheae, they should need the most oxygen to be able to breathe. Only when environmental oxygen is high will it push to the deepest reaches of the tracheae.

If this hypothesis is correct, the smallest bugs should be able to deliver adequate oxygen to the tissues even in an atmosphere with low oxygen, since their tracheae are very short. This difference ought to be particularly apparent when the insects are challenged with an oxygen consuming activity, such as flying or jumping.

These results are precisely what Harrison sees in the laboratory.

Graduate student Scott Kirkton works with Harrison to test the aerobic performance of grasshoppers given controlled amounts of oxygen. They have found that smaller grasshoppers can hop nonstop in sub-atmospheric oxygen levels. In fact, the smallest ones are not even bothered when oxygen is as low as 5 percent.

In contrast, when larger grasshoppers are placed in the same environment, they can’t keep up. They wear out faster, and their hopping rates quickly drop to zero.

However, if Kirkton gives them an extra dose of oxygen—say 40 percent—large grasshoppers demonstrate their oxygen sensitivity by jumping more. The oxygen-stimulated boost in performance suggests that larger insects do require more oxygen.

A similar pattern emerges for dragonflies. As oxygen in the atmosphere is reduced, the dragonflies go from effortless flight to increasingly futile exertion. Eventually, when oxygen is set at a critically low level, they can’t even get off the ground. Like the hoppers, dragonflies perform better with increased oxygen, flying more energetically and breathing faster.

Whether or not the Paleozoic oxygen pulse actually triggered the rise of insect gigantism, Harrison is motivated by the more general applications of his work.

“We are most interested in defining broad scaling rules about how respiration changes with body size,” he says. “There is a tight relationship between body size and metabolic rates in all animals, but no one has been able to determine why this is so.”

From insects to elephants, the pattern is impressively consistent. Smaller species tend to live fast and die young. They have speedy metabolic rates and short life spans. Bigger animals are generally longer-lived, and they have more leisurely metabolic rates.

Since high metabolism demands high oxygen delivery, Harrison suspects that respiratory mechanisms may provide some valuable clues about the nature of this basic relationship.

Harrison plans to examine insect flight at higher altitudes, where oxygen naturally decreases. For this work, the record-setting metabolic rates and flight abilities of bees make them natural subjects.

Says Harrison, “What I’d really like to do is take the whole family on a drive up Pike’s Peak Road. We’d throw bees out the window every 1000 feet to see if they can fly.”—Danika Painter

The National Science Foundation supports ASU research on how the respiratory physiology of insects affects their body size. For more information, contact Jon F. Harrison, Ph.D., Department of Biology, College of Liberal Arts and Sciences, 480.965.9459. Send e-mail to

it's ah facinatin place,this orb called earth.


--- Quote from: capodetutticapi on February 10, 2009, 11:13:02 PM ---it's ah facinatin place,this orb called earth.

--- End quote ---

yeah and according to the Bible thumpers it is in ONLY about 4000-6000 years old yuh know.

look at a picture of a christian here

Coming soon to extinction..Christianity and religion...just be patient and let evolution have its way!

As a Protestant bishop in a Catholic land, Ussher’s obsession with providing an accurate Biblical history stemmed from a desire to establish the superiority of the scholarship practiced by the clergy of his reformed faith over that of the Jesuits, the resolutely intellectual Roman Catholic order. (Ussher had absolutely nothing good to say about “papists” and their “superstitious” faith and “erroneous” doctrine.) Ussher committed himself to establishing a date for Creation that could withstand any challenge. He located and studied thousands of ancient books and manuscripts, written in many different languages. By the time of his death, he had amassed a library of over 10,000 volumes.

The date forever tied to Bishop Ussher appears in the first paragraph of the first page of The Annals. Ussher wrote: “In the beginning, God created heaven and earth, which beginning of time, according to this chronology, occurred at the beginning of the night which preceded the 23rd of October in the year 710 of the Julian period.” In the right margin of the page, Ussher computes the date in “Christian” time as 4004 B.C.

Although Ussher brought stunning precision to his chronology, Christians for centuries had assumed a history roughly corresponding to his. The Bible itself provides all the information necessary to conclude that Creation occurred less than 5,000 years before the birth of Christ. Shakespeare, in As You Like It, has his character Rosalind say, “The poor world is almost six thousand years old.” Martin Luther, the great reformer, favored (liking the round number) 4000 B.C. as a date for creation. Astronomer Johannes Kepler concluded that 3992 B.C. was the probable date.

As paleontologist Stephen Jay Gould points out in an essay on Ussher, the bishop’s calculation of the date of Creation fueled much ridicule from scientists who pointed to him as “a symbol of ancient and benighted authoritarianism.” Few geology textbook writers resisted taking a satirical swing at Ussher in their introductions. How foolish, the authors suggested, to believe that the earth’s geologic and fossil history could be crammed into 6,000 years. Gould, while not defending the bishop’s chronology, notes that judged by the research traditions and assumptions of his time, Ussher deserves not criticism, but praise for his meticulousness. The questionable premise underlying Ussher’s work, of course, is that the Bible is inerrant.

Ussher began his calculation by adding the ages of the twenty-one generations of people of the Hebrew-derived Old Testament, beginning with Adam and Eve. If the Bible is to be believed, they were an exceptionally long-lived lot. Genesis, for example, tells us that “Adam lived 930 years and he died.” Adam’s great-great-great-great-great-grandson, Methuselah, claimed the longevity record, coming in at 969 years. Healthier living conditions contributed, or so it was believed, to the long life spans of the early generations of the Bible. Josephus, a Jewish theologian writing in the first century, explained it this way: “Their food was fitter for the prolongation of life…and besides, God afforded them a longer lifespan on account of their virtue.”

To calculate the length of time since Creation, knowledge of more than the ages of death of the twenty-one generations was required; one also needed to know the ages of people of each generation at the time the next generation began. Fortunately, the Bible provided that information as well. For example, Genesis says that at the time Adam gave birth to his first son, Seth, he had “lived 130 years.” Augustine (as might a lot of people) wondered how a 130-year-old man could sire a child. He concluded that “the earth then produced mightier men” and that they reached puberty much later than did people of his own generation.

The Old Testament’s genealogy took Ussher up to the first destruction of the Temple in Jerusalem during the reign of Persian king Nebuchadnezzar. Ussher’s key to precisely dating Creation came from pinning down, by references in non-Christian sources, the precise dates of Nebuchadnezzar’s reign. He finally found the answer in a list of Babylonian kings produced by the Greek astronomer Ptolemy in the second century. By connecting Greek events to Roman history, Ussher tied the date of Nebuchanezzar’s death (562 B.C.) to the modern Julian calendar. Once the date of 562 B.C. was calculated, there remained only the simple matter of adding 562 years to the 3,442 years represented by the generations of the Old Testament up to that time: 4004.

Ussher next turned his attention to identifying the precise date of Creation. Like many of his contemporary scholars, he assumed that God would choose to create the world on a date that corresponded with the sun being at one of its four cardinal points—either the winter or summer solstice or the vernal or autumnal equinox. This view sprang from the belief that God had a special interest in mathematical and astronomical harmony. The deciding factor for Ussher came from Genesis. When Adam and Eve found themselves in the Garden of Eden, the fruit was invitingly ripe. Ussher reasoned, therefore, that it must have been harvest time, which corresponded with the autumnal equinox: “I have observed that the Sunday, which in the year [4004 B.C.] aforesaid, came nearest the Autumnal Aequinox, by Astronomical Tables, happened upon the 23 day of the Julian October.”

A London bookseller named Thomas Guy in 1675 began printing Bibles with Ussher’s dates printed in the margin of the work. Guy’s Bible’s became very popular—though their success might be as much attributed to the engravings of bare-breasted biblical women as to the inclusion of Ussher’s chronology. In 1701, the Church of England adopted Ussher’s dates for use in its official Bible. For the next two centuries, Ussher’s dates so commonly appeared in Bibles that his dates “practically acquired the authority of the word of God.”

this is where science and religion clash.


--- Quote from: capodetutticapi on February 10, 2009, 11:25:08 PM ---this is where science and religion clash.

--- End quote ---

Jes anodder picture of ah person who believe in a God in the sky and does eat pie so when dey die, dey go get wings and fly, easy on first try, no more will dey cry as they leave this earth bye and bye, dem a dreaming lie, ah know dis as ah did spy, and de shit make me sigh, to see dey eh go get de bligh dey looking for u in de sky!


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